What's holding me back with the Fulla is the usability. If the volume knob is difficult to use, I dont want to be frustrated with it at all times. Considering a Magni 2/Modi 2 Combo.. but not sure if its worth the increase in the price, SQ and aesthetics wise. Also, how powerful is the combo compared to the fulla? if in the future I intend to buy 600ohm headphones, would the fulla be able to drive them or the combo will be better?